Steroid receptors in human endometrium. Comparison of data obtained by three different methods

An improved micromethod for the determination of biochemically active estrogen and progesterone receptors in parallel to comparative histological examination of a single piece of tissue

An improved radioreceptor assay of unfixed cryostat sections of human target tissues has been developed. Sections collected on glass coverslips were immediately incubated with 5 nM concentrations of either tritiated estradiol-17 beta for estrogen receptor (ER) or ORG 2058 for progesterone receptor (PR) determination. For quantitation, receptor-bound and free hormone were separated by isoelectric focusing (IEF). The assay allows the determination of steroid hormone receptors and comparative histological examinations in immediately neighbouring serial sections of a single piece of tissue. Biochemically, the validity of the assay procedure was evidenced by Scatchard analysis, by ligand and tissue specificities, by the linear relations of receptor and protein concentrations and the number of sections per test tube. Diagnostically, we compared the routine (6 point DCC-Scatchard) procedure for breast cancer analysis with the section method. A good correlation for ER and a less pronounced correlation for PR was found. Statistically, the precision of the method was verified by low deviations of duplicate determinations, low day-to-day variations and low inter-assay variations.

Steroid receptors analysis in human mammary tumors by isoelectric focusing in agarose

A high resolution and quantitative method for isoelectric focusing has been developed to separate the isoforms of estrogen and progesterone receptors in human mammary tumor cytosols stabilized by sodium molybdate. Agarose gels (0.5%) were used. Six samples can be analyzed on one gel in about 2 h, and 35-microliters samples are sufficient to determine the estrogen receptor isoform pattern. The constant yields and the reproducibility of data allow a quantitative analysis of these receptors. Four estrogen receptor isoforms have been observed (pI 4.7, 5.5, 6, and 6.5), isoforms with pI 4.7 and 6.5 being present in all tumors. After incubation at 28 degrees C in high ionic strength, the comparison of isoelectric focusing and high-performance size exclusion chromatography patterns of estrogen receptor confirms the oligomeric structure of the pI 4.7 isoform and suggests a monomeric structure for the pI 6.5 isoform. Under the same conditions of analysis, only one progesterone receptor isoform has been detected with pI 4.7.

Steroid receptor content in human ovarian tumors: survival of patients with ovarian carcinoma related to steroid receptor content

Steroid receptors were measured in 31 malignant and 29 benign or semimalignant ovarian tumors in a prospective study. Estrogen receptors (ER) were found more often in highly differentiated malignant tumors (86%) than in poorly differentiated ones (23%). No such difference was found for progesterone receptor (PR). Receptor content was not related to clinical stage. The median survival of patients with PR+ or ER+/PR+ malignant tumors was 30 and 31.5 months, respectively, compared to 10 and 9 months for those with receptor negative tumors. This positive prognostic information could not be demonstrated for ER alone. Receptor content and distribution were similar in benign and semimalignant tumors. Measurement of hormone receptors in ovarian cancers can thus give valuable prognostic information.